Matthew Flugence, 20, was arrested in the case July 16, the day authorities found Ahlittia's body in a trash can down the street from her mother and stepfather's apartment in Harvey.

Flugence's brother Russell, 21, was arrested on suspicion of obstructing justice in Ahlittia's death, Jefferson Parish Sheriff Newell Normand said. Russell Flugence had information about the crime that he didn't come forward with, and he also had information implicating his brother, the sheriff asserted.

Matthew Flugence told investigators that he killed Ahlittia after finding her early July 13 outside the Harvey apartment where her mother and her stepfather -- Flugence's uncle -- lived, Normand said.

The investigation began after Ahlittia's mother awoke July 13 to find her gone from the apartment, authorities said. The girl was living with her mother for the summer, but normally lived with someone else in Donaldsonville, Normand said.

After she was reported missing, investigators spent July 13 combing the neighborhood, looking in alleys, Dumpsters and boarded-up fourplexes. They found a pool of blood in one of the buildings, Normand said, and when DNA results came back the evening of July 15 showing the blood belonged to Ahlittia, investigators searched the area again.

That's when they found the girl's body in a garbage can, wrapped in a blanket from her house and covered in a garbage bag, Normand said.

Investigators looked at the garbage can during their first search of the neighborhood, so they know the body was put inside sometime after July 13, he said.